A man denied a £500 grant after being told to isolate by the NHS phone app has said it was a "kick in the teeth."
In Wales, the self-isolation support scheme for low-earners is still not available to people who are notified by the app.
Taxi driver David Miller lost 10 days of work by isolating and had no grant.
The Welsh Government said it was working with councils to "identify what other alternatives, including manual solutions, can be put in place".
The self-isolation support scheme is intended to help with loss of earnings for those told to self-isolate who cannot work from home.
In Wales it is also for parents and carers on low incomes with children who are self-isolating.
In December it was reported that the NHS Track and Trace app for Wales and England had been updated to allow people notified that they must isolate to claim the £500.
But while users in England notified by the app can claim the payments after going through an identity-verification process, people in Wales cannot.
Mr Miller, from Pembroke, received a notification on the NHS app on Boxing Day telling him to self-isolate for 10 days.
As a recipient of housing benefit he should have been able to claim the £500 grant to offset his loss of earnings.
But when he applied via his local authority he was told they could not pay him.
"It was a kick in the teeth really. I've had no help since the pandemic started, financially, from the government.
"They ask you to self-isolate to protect others and then you get no financial support so you have got to make a choice of shall I go out and put people at risk because I need to pay my bills or should I struggle financially and stay home?
"My choice is listen to the app, stay at home, self- isolate."
But Mr Miller thinks without the financial support, others are not making the same choice
"I have a lot of friends in the taxi trade who wouldn't download the app because of that.
"I know people will not adhere to it, I know that for a fact because I've spoken to them.
"They can't do it financially."
'I lied to my doctor for a sick note'
A mother-of-two from Carmarthenshire, who didn't want to be named, told BBC Wales Live she lied to her doctor to get a sicknote after missing out on the £500 grant.
She had to stay home to look after her son who had been told to isolate, meaning she would lose nearly £500 in wages.
She wasn't eligible for the grant as she is not on benefits, and she would have had to take unpaid leave if she did not have a doctor's note.
"It's horrible. I still feel really guilty about it now, but needs must.
"When you have to feed your children you do what you have to do."
The Welsh Government has told Wales Live more than 5,000 payments have been made since the scheme's launch.
During that period around 300,000 positive cases and close contacts were identified by the Test, Trace, Protect system.
The charity Resolution Foundation said the figures and its own research showed the payment was "not reaching enough people".
It has called for a bigger scheme that would operate in a similar way to the job retention furlough programme.
Maja Gustafsson, from the foundation, said: "Not supporting the people who fall ill or risk spreading the virus further is going to be devastating for everyone.
"Investing in people so that they can do the right thing will be money well spent."
A Welsh Government spokesman said: "Unfortunately, making the necessary changes to enable people to apply for self-isolation payments after being told by the app to self-isolate could take a little while to deliver for Welsh app users.
"We are urgently working with local authorities to identify what other alternatives, including manual solutions, can be put in place as soon as possible, to ensure people told to self-isolate via the app are able to apply for the £500 self-isolation payment if they are eligible."
- Wales Live, BBC One Wales, 19 January at 22:35 GMT